From Introduction:
The Ἱππαρείωνες once ruled over the entire Plain of Golden Grasses, and in ages past they would come sweeping down upon the civilized world in great marauding hordes. But that was before they gave themselves over to the gods of chaos on the eve of extinction.
One day in autumn, the behemoths came lumbering down upon them and sacked their temple, which lay in the very middle of the Golden Grasses, at the foot of the Spire of Law. With their spiritual centre destroyed, what was left of Hippareionian culture crumbled. Kamikaze-like raids into neighbouring cultures became the norm, and death in the midst of glorious battle was considered to be the highest achievement of all. But some small portion of the Hippareiones wanted to live on more than anything else, and so they turned away from the traditions of their forebears and gave themselves over to the gods of chaos and darkness.
The Hippareiones now live in the shadows of other, greater civilizations, as nomads and cave-dwellers, as merchants of exotic goods and hierophants of strange pantheons. They hate dwarves most of all, and vie with them for control of mountainous territory and vaulted caverns where they can stay out of sight and undisturbed. Occasionally serving in mercenary bands alongside humans or even as gladiators in the arenas of the minotaur kings, their main objective, culturally, is to increase the power of their gods.